Preparation of polyalkenamers

ABSTRACT

Process for the ring opening polymerisation of cyclomonoolefins by contacting the cyclomonoolefins with a catalyst comsisting of A. A REACTION PRODUCT OF A TUNGSTEN OR TANTALUM HALIDE WITH AN ACETAL AND B. AN ORGANO COMPOUND OF A METAL OF GROUPS Ia to IVa of the Periodic Table THE MOLAR RATIO OF TUNGSTEN: METAL OF GROUPS Ia to IVa being from 1:03 to 1:10 and the molar ratio of tantalum: metal of groups Ia to IVa being from 1:1 to 1:10.

United States Patent [191 Schiin et a1.

[ June 18, 1974 PREPARATION OF POLYALKENAMERS [73] Assignee: Bayer Aktiengesellschaft,

Leverkusen, Germany [22] Filed: Nov. 20, 1972 [21] Appl. No.: 308,012

Related U.S. Application Data [62] Division of Ser. No. 111,763, Feb. 1, 1971, Pat. No.

[30] Foreign Application Priority Data Feb. 15, 1970 Germany 2006776 [52] US. Cl. 260/93.l, 260/82.1, 260/88.2 B,

260/88.2 R [51] Int. Cl. C081 1/34 [58] Field of Search 260/93.l, 88.2 B, 82.1

[56] References Cited UNITED STATES PATENTS 3,459,725 8/1969 Natta et a1. 260/93.1 FOREIGN PATENTS OR APPLICATIONS 3/1967 Great Britain 260/93.1

Primary Examiner-Stanford M. Levin Attorney, Agent, or FirmConno11y and Hutz [5 7] ABSTRACT Process for the ring opening polymerisation of cyclomonoolefins by contacting the cyclomonoolefins with a catalyst comsisting of a. a reaction product of a tungsten or tantalum halide with an acetal and b. an organo compound of a metal of groups 1a to lVa of the Periodic Table the molar ratio of tungsten: metal of groups In to Na being from 1:03 to 1:10 and the molar ratio of tantalum: metal of groups 1a to IVa being from 1:1 to 1:10.

5 Claims, No Drawings 7 This application is a division of application Ser. No.

111,763 filed Feb. 1, 1971 and now U.S. Pat. No. 3,753,928.

Cyclopentene can be polymerised using organometallic mixed catalysts obtained from alkyl aluminium compounds and tungsten salts. 'Polymerisation is accompanied by ring opening and unsaturated high molecular weight hydrocarbons are obtained whose double bonds are predominantly in the trans configuration. A process for the preparation of such transpolypentenamers by bulk polymerisation of cyclopentene has been disclosed in British Patent Specification No. 1,010,860. This process, however, requires large quantities of catalyst and temperature control is difficult, particularly if polymerisation is not stopped after only a low conversion. Moreover, the long reaction times and low conversions are disadvantages which cannot be overlooked. British Patent Specification No.

1,062,367 relates to a process for the preparation of trans-polypentenamers in which catalysts are used which are obtained by reacting tungsten salts with oxygen compounds containing OO or O-H bonds and organic aluminium compounds. The quantities of catalyst required, however, are again very high and the conversions, being in the order of 30 50 percent, are too low to be of technical interest.

The catalysts for this process are prepared in a heterogeneous reaction between tungsten salts and an aluminium alkyl compound, if desired, with the addition of a third component, and this reaction is not reproducible. It is only in solution that heavy metal complex catalysts can be obtained in a reproducible manner and it is only with such catalysts that the polymerisation process becomes controllable.

1f hydrocarbons are used as solvents for preparing such catalysts, however, the quantity of solvent required is very large because tungsten salts are only sparingly soluble in hydrocarbons. In addition, a large quantity of solvent is required for the polymerisation itself, and this solvent subsequently has to be recovered. Furthermore, the recovered hydrocarbon solvent must be carefully purified before it can be used again because otherwise any olefines contained in it are liable to undergo Friedel-Crafts reactions with the tungsten salts to form completely insoluble compounds which contain tungsten.

The present invention relates to catalysts for the ring opening polymerisation of cyclopentene which are readily soluble in hydrocarbons and halogenated hydrocarbons which catalysts consist of a a. a reaction product of a tungsten halide or tantalum halide with an acetal and b. an organo compound of a metal of groups la to lVa of the Periodic Table preferably an organo aluminum compound, the molar ratio of tungsten: metal of groups la to Na being between 1:03 and 1:10 and the molar ratio of tantalum: metal of groups la to Na being be tween 1:1 and 1:10.

Another object of the invention is a process for the ring opening polymerisation of cyclopentene in solu tion in an organic solvent in the presence of a catalyst, consisting of a. a reaction product of a tungsten halide with an acetal and halide or tantalum ration of the catalysts may advantageously be the fluo- Y b. an organo compound of a metal of groups la to lVa of the Periodic Table preferably an organo aluminum compound, the molar ratio of tungsten: metal of groups la to Na being between 1:0.3 to 1:10 and the molar ratio of tantalum: metal of groups la to Na being between lzl and 1:10.

Preparation of the catalysts:

The tungsten or tantalum halides used for the preparides, chlorides and bromides and oxyhalides, such as WCI WOCl WCl WBr WF TaCl and TaBr Suitable acetals are, in particular, compounds of the following formula:

QCHw Hm.

Cl CCH(OCH To prepare the catalysts, the tungsten or tantalum halides may first be reacted with the acetals in solution in aliphatic, cycloaliphatic oraromatic hydrocarbons or halogenated hydrocarbons. The following are examples of suitable solvents: pentane, hexane, isooctane, benzene, toluene, xylene, cyclohexane, chlorobenzene,

chloroform, carbontetrachloride, tetrachloroethane and trichloroethylene. It is advantageous to use the same solvent as that which is used for the subsequent polymerisation.

The reaction temperature for the reaction of the tungsten and tantalum halogen compounds with the acetals may be between 0C. and C. Temperatures of between 15C. and 60C. are preferably employed.

The molar ratio of tungsten or tantalum halide to acetal may be between 1:06 and l:.\', where x is the number of halogen atoms of the metal halide. The best results are generally obtained with 0.75 2 mols of acetal per mol of metal halide.

For the reaction of the tungsten or tantalum halides with the acetals, unsaturated or saturated solutions (possibly with sediment) ofthe metal halides in one of thesolvents mentioned above may be used as starting material, the acetal being added slowly and the components being mixed at the same time. The reaction is slightly exothermic so that cooling may be required to maintain a particular reaction temperature or the rate of addition of the acetals must be suitably controlled. Any metal halide sediment which is present slowly dissolves in the course of the reaction. The solutions obtained are generally deep red to brown in colour. The colour is slightly less intense if large quantities of acetal are present. The reaction may also be carried out by introducing an acetal solution into the reaction vessel and adding the tungsten or tantalum halide.

The reaction times depend mainly on the concentration and the reaction temperature as well as on the particle size of the metal halides which form a sediment. They are generally in the order of 15 to 120 minutes. For example, reaction times of 30 60 minutes are sufficient at 30C.

The reaction products of tungsten or tantalum halides and the acetals, in contrast to the parent halides, are easily soluble in the solvents used, so that solutions which have a high concentration of tungsten or tantalum can easily be prepared. In contrast to the original halides, they result in much more active catalysts for the polymerisation of cyclopentene, so that the required catalyst amount is reduced and yet high conversions are achieved. Even the combination of tungsten halide and peroxide or alcohol according to British Patent Specification No. 1,062,367 has an inferior activity as compared to the catalysts according to the invention.

The acetals used according to the invention also increase the catalyst activity if they are used as cocatalysts for tungsten or tantalum halide catalysts, but the activity obtained is nowhere near as great as the activity of catalysts obtained from the reaction products according to the invention.

The second catalyst component used consists of organic aluminium compound, e.g. aluminium trialkyls, aluminium alkyl halides, aluminium alkyl hydrides or aluminium alkyl compounds which have alkoxy or amino groups; alkyl, alkoxy and secondary alkyl amino radicals containing 1 6 carbon atoms being preferred. Examples are: Al(C H Al(C,H Al(C H H, 6 l3)3v 2 s)2 L -I 9)2 L z 5) z. 4 a) 2 2 s)2 s)2 and 2 5)1.5 r.s- One may also use mixtures of such compounds or other metal alkyls which have a comparable activity, such as tin alkyls, tin alkyl hydrides (especially tin dialkyl dihydrides) or zinc alkyls (alkyl also containing preferably 1 to 6 carbon atoms). The quantity of organic aluminum compound is chosen so that the molar ratio of WzAl 1:0.3 to 1:10 and the molar ratio ofTazAl 1:1

The preparation of the catalyst itself is carried out by combining the reaction product of the acetal and metal halide at temperatures of between 20C and +60C, preferably 10C and +C with the organo metal compound. Generally, a solution of the reaction product is introduced into the reaction vessel and the organic aluminum component (if desired in the form of a solution in one of the solvents mentioned above) is added thereto, preferably with the exclusion of air and moisture. The sequence may be reversed if desired.

The catalyst is immediately readyfor use.

If desired, the 'catalyst'component may be added to a solution of the monomer, polymerisation then setting in at once. This method is preferred.

Polymerisation:

Polymerisation is generally carried out with 5 50 percent, preferably 10 30 percent solutions of cyclopentene in one of the solvents mentioned above. Hydrocarbon solvents are particularly suitable for tungsten catalysts, and halogenated hydrocarbons are particularly suitable for tantalum catalysts. As already mentioned above, the catalysts may be produced in the solution of the monomer or the finished catalysts may be added to this solution. The quantity of catalyst pref erably corresponds to 0.01 4. preferably 0.1 to 2 mMol of tungsten or tantalum per g. of cyclopentone.

The ring opening polymerisation may be carried out not only on cyclopentene but also on other cycloolefins, e.g. cyclomonoolefins having 5 to 12 carbon atoms as cycloheptene, cyclooctene, cyclododecane. Furthermore, the catalysts according to the invention can be used for copolymerising cyclomono olefins (as defined above) with monocyclic or polycyclic diolefins such as dicyclopentadiene, norbornene, norbornadiene or polyolefins, e.g. aliphatic diolefins such as butadiene, isoprene, in an amount not exceeding 30 percent, preferably 10 percent by weight of the total monomer mixture.

The polymerisation temperatures maybe adjusted to between 20C. and +50C., in which case the polymerisation times are in the range of 10 minutes to 4 hours. The molecular weight of the transpolypentenamer obtained according to the invention can be influenced to a certain extent by the concentration of tungsten or tantalum, the molar ratio of aluminium to tungsten (tantalum), the nature of the aluminium component and the quantity of acetal as well as by the presence of a-olefines and dienes.

When the required degree of conversion has been reached, polymerisation can be stopped by the addition of alcohols, carboxylic acids and/or amines. Stabilisers and age resistors, e.g. one of the usual products such as phenyl-B-naphthylamine, 2,6-di-tert.-butyl-4 methylphenol or 2 2-dihydroxy-3,3-di-tert.-butyl- 5,5'-dimethyldiphenylmethane may be added in quantities of 0.2 3 percent. Adhesifying agents, resins and oils may also be added at this stage.

The polymers can be isolated from their solution by precipitation with alcohols or, preferably in technical processes, by driving off the solvent with steam. The lumps of polymer obtained can then be dried in a drying cupboard, if desired under vacuum, in a screw .or on a conveyor drier. The trans-polypentenamer obtained is. a rubber-like polymer. It can be cross-linked with the known vulcanising agents and worked up into the usual rubber products.

The readily soluble reaction products of tungsten or tantalum halides and acetals used according to the invention can be accurately and reliably closed so that the composition of catalyst is readily reproducible. They are stable on storage, i.e. the activity of the catalysts prepared from their solutions does not change even after prolonged storage of the solutions. Important requirements for technical application of tungsten and tantalum catalysts for the polymerisation of cyclopentene are thus fulfilled. The trans-polypentenamers obtained using the catalysts according to the invention have excellent properties for working up as well as good properties as vulcanisates. Example 1 a. Reaction of WCl with Cl-1 (OCH CH Cl) in the molar ratio of 110.75 5 parts of WCl were dissolved in 140 parts of tolueneat room temperature. 1.63 parts of C H (OC H CH C l) dissolved in parts of toluene were added to the deep blue solution at C. The temperature of the solution rose by 4C. and the colour changed from blue to deep brown. The reaction mixture was stirred for 1 hour at 25C. b. Polymerisation experiments on cyclopentene Monomer solutions were prepared from 1000 parts of toluene and 200 parts of cyclopentene in a nitrogen atmosphere in vessels equipped with stirrers with exclusion of moisture so that the water content was less than 10 ppm. The tungsten component was added to the monomer solutions at 10C. in the form of the solution prepared under a. The solutions were then colled to -5C. and the aluminium alkyl component was added with stirring. The polymerisations started at once; the polymerisation temperatures were maintained between 5C. and 0C. The polymerisations were stopped after 3 hours by the addition of 0.5 percent of 2,2- dihydroxy 3,3-di-tert.-butyl-5,5-dimethyldiphenylmethane and 1.5 percent of ethanolamine (based on the monomer) in each case dissolved in parts of ethanol and parts of benzene. The polymers were precipitated with ethanol and dried in vacuum at 50C. Catalyst composition, yields and properties of the polymers are summarised in Table l. I H

Table 1 Defo/defo elasticity 1 100/31 lR-trans-content 91.5%

Example 3 Cyclopentene was polymerised with the tungsten solution of Example 2a in the same way as in Example 2b. 0.45 millimols of tungsten was used for 100 g of cyclopentene. Al(C l-l Cl (ethyl aluminium sesquichloride) was added as the aluminium component in the form of a 10 percent solution in toluene at -5C so that the W/Al molar ratio was 112.0. The yield was 81 percent after 3 hours. After working up as in Example 111. the polymer had the following properties:

Mooney viscosity ML 4' 100C 101 DefO/defo elasticity 700/ l 5 IR: trans-linkages 91.9%. Example 4 a. Reaction of WCl with CH (OCH 5 parts of WCl were dissolved in 1 10 parts of toluene at 30C, and 0.96 parts of CH (OCH was added (with stirring, nitrogen and exclusion of moisture). The temperature of the solution rose to 32C and the colour changed from dark blue to deep brown. The solution was then stirred for 1 hour at 30C.

b. Polymerisation of cyclopentene 200 g of cyclopentene were polymerised under the same conditions as in Example 1b. The quantity of tungsten in the form of its reaction product with CH (OCH was 0.45 millimol per 100 g of cyclopentene. The cyclopentene contained 0.075 percent of butene-l. The aluminium component used was Al(C H Cl, the amount used being such that the molar ratio of Al/W was 2:1. After a polymerisation time of 3-hours, the polymer yield was Experiment Millimol of Aluminium alkyl Molar Yield (1;) Mooney Defo/ 1R tungsten per ratio ML 4 defo elasticity trans-content 100' g of Al/W 100C monomer a) 0.45 A1(C,H,,) 2.5 65 1075/6 b) 0.5 Al(C,l-1, C 2.5 81 2 06 1000/32 91 8 c) 0.4 A1(C,H,,),Cl 2.5 81 2 87 142 1950/34 912 d) 0.45 Al( zH; Cl 2.0 77 126 1300/20 91.0 e) 45 Al(CzH5)|..-,Cl|..-. 2.5 8 2 2.00 68 400/13 91.1

a) 200 ppm of butane-1 were added to the monomer as molecular weight regulator.

Example 1b.

0.45 mMol of tungsten in the form of the solution de- 6Q scribed in Example 2a were used for g of cyclopentene, and added to the monomer solution at 0C. Al(C H Cl was added as the aluminium component in the form of a 10 percent solution in toluene at 5C, the molar ratio of Al/W being,65

The yield after 3 hours was 81%. Mooney viscosity ML4' 100C 82 Mooney ML 4' Defo/defo elasticity 550/ 1 3 1R: trans-bonds: 91.7%

In an experiment carried out for comparison, WCl was used in the form of a 4 percent solution in toluene instead of the reaction product of WCl and CH (OCH The polymer yield was only 23 percent, intrinsic viscosity (1,) 5.1, lR-trans content 89.8 percent.

Example 5 a. Reaction of WCl with CH CH(OC H 5 parts of WCl were dissolved in 130 parts of toluene, and 2.24 parts of CH CH(OC H were added at 25C (with stirring, nitrogen and exclusion of moisture). The reaction was slightly exothermic (temperature rise 3C) and the colour of the solution changed to dark brown. The solution was stirred for 1 hour at 30C.

b. Polymerisation of cyclopentene Polymerisation was carried out as in Example 1b,

using the tungsten solution prepared under Example a. 0.45 millimol of tungsten was used for 100 g of cyclopentene The aluminium component used was A1(C. .l-l -,Cl (aluminium ethyl sesquichloride), and the molar ratio of Al/W was 3:1.

Polymer yield after 2% hours: 70%

Defo plasticity/defo elasticity 1950/ lR content of trans-double bonds 90.7%

Example 6 a. Reaction of WCl with C1 CCl-l(OCH 5 parts of WCI were dissolved in 130 parts of toluene, and 3.65 parts of the chloral acetal Cl CCH(OCH were added with stirring. The process was carried out under nitrogen with exclusion of moisture. The temperature rose from 26C to 28C. Stirring was then continued for 2 hours at 25C. A deep brown solution was obtained.

b. Polymerisation of cyclopentene Polymerisation was carried out as in Example lb. Tungsten was used as a solution of the reaction product of tungsten hexachloride with Cl -,C-CH(OCH,,) in an amount of 0.45 mmols of tungsten. The polymerisation had the following We claim:

1. A process for preparing a polymer of a cyclomonoolefin by ring opening which comprises contacting a 5 to 50 percent by weight solution of a cyclomonoolefin in an inert organic solvent with a catalyst at a temperature of from 20 to 60C., said catalyst comprising I a. the reaction product of a tungsten or tantalum halide and from 0.75 to 1.5 mols of an acetal per mol of halide at a temperature of from 0 to 100C said result acetal being of the formula aluminum molar ratio conversion Defo/DefolR-transcomponent 3 hours elasticity content Al(C,H ),Cl 2,5 l 65 4850/39 I 90,8 Al(C H,), .,Cl 2,5 1 67 4350/39 91,5

Example 7 a. Reaction of WC] with o R OR 5.1 parts WCl were dissolved in 140 parts toluene and 3.5 parts of benzaldehyde-diethylacetale was added at 20C with stirring under nitrogen and with exclusion of moisture. The temperature rose by 3C. The deep brown solution obtained was stirred for 1 hour at C.

b. Polymerisation of cyclopentene According to the method described in Example lb cyclopentene was polymerised using the reaction product described in Example 7a. The amount of tungsten was 0.5 mmols/100 g cyclopentene. Al(C H.-,) Cl, was the second catalyst component, its amount was selected so that the molar ratio Al:W was 3:1. I

Polymer yield after 2 hours: 54%

Defo plasticity/defo elasticity 2500/20 lR-content of trans double-bonds: 88.8%

Example 8 4.3 g TaCl were dissolved in 600 ml of chlorobenzene under exclusion of air and moisture. Then 300 ml of cyclopentene and 1.6 ml of dichlorodiethylformal were added. A completely clear solution, having a strong yel- LII wherein R is hydrogen, alkyl, haloalkyl, aryl, haloaryl, alkaryl or haloalkaryland R is alkyl, haloalkyl, aryl, haloaryl, alkaryl or haloalkaryl and b. an organo compound of a metal of Group la to Na of the Periodic Table. the molar ratio of tungstenzmetal of Groups la to lVa being from 1:03 to 1:10, the molar ratio of tantalum:- metal of Groups la to Na being from 1:1 to 1:10 and said catalyst being present in an amount corresponding to 0.1 to 4 mmol tungsten or tantalum per g of cyclomonoolefin.

2. A process according to claim 1 wherein said tungsten or tantalum halide-is tungsten hexachloride or tantalum pentachloride.

3. A process according to claim 1 wherein said catalyst constituent b is an aluminum trialkyl, aluminumdialkylhalide or aluminumdihalide, or mixtures thereof.

4. A process according to claim 1 wherein said cyclomonoolefin is cyclopentene.

5. A process according to claim 1 wherein said cyclomonoolefin is a mixture of a cyclomonoolefin and not more than 30 percent by weight based on the total monomer mixture of a monocyclic or a polycyclic diolefin or an aliphatic diolefin. 

2. A process according to claim 1 wherein said tungsten or tantalum halide is tungsten hexachloride or tantalum pentachloride.
 3. A process according to claim 1 wherein said catalyst constituent b is an aluminum trialkyl, aluminumdialkylhalide or aluminumdihalide, or mixtures thereof.
 4. A process according to claim 1 wherein said cyclomonoolefin is cyclopentene.
 5. A process according to claim 1 wherein said cyclomonoolefin is a mixture of a cyclomonoolefin and not more than 30 percent by weight based on the total monomer mixture of a monocyclic or a polycyclic diolefin or an aliphatic diolefin. 